Research last year found that almost half of adults – 17 million – have poor maths skills, leaving them struggling to manage family finances, calculate change and use transport timetables.

Experts warned that low-level maths was worn as a “badge of honour” by too many adults, even among professional classes with good jobs in the media and civil service.

A recent study by US academics found that parental support was key in driving up standards among children, with mothers and fathers having a greater impact than schools themselves.

But the latest report by Pearson found that 30 per cent of parents “don’t feel confident enough in their own maths skills to help their children with their primary school maths homework”. Some 53 per cent insisted they struggled to understand the new maths teaching methods used in modern classrooms.

The conclusions follow a decision by ministers to reintroduce traditional methods of calculation into primary school maths exams because of concerns children were increasingly being taught using “clumsy, confusing and time-consuming” methods of working out. This includes so-called “chunking” and “gridding” where pupils are encouraged to break problems down into numerous component stages before an answer is reached.

Commenting on the study, Carol Vorderman, the TV presenter who has carried out a review for the Conservatives into maths teaching, said: “Studies have shown that if parents help their children with homework they are more likely to succeed at school. It is therefore worrying that so many parents lack confidence in their own maths skills.

“It’s imperative that children are given the opportunity to learn maths in a way that is fun, accessible and engaging, both at home and in the classroom.”

Researchers surveyed 2,005 parents of school-age children on their attitudes towards maths.

They were also presented with a list of 10 questions suitable for pupils in the final three years of primary school – and the first year of secondary education.

Only five per cent could answer all 10 questions correctly, it was revealed.

Some 15 per cent of parents even struggled with a simple fractions question aimed at eight and nine-year-olds. They were presented with a list of fractions – including 2/8, 10/40, 4/8 and 5/20 – and asked which one was not equivalent to ¼.

In all, a quarter of parents correctly answered just four out of 10 questions or less.

The study coincided with the launch of a new Maths Made Easy resources pack – backed by Miss Vorderman – which allows parents and their children to test themselves on a range of age-specific questions.